Field
The present invention relates to a light emitting device and a method of fabricating the same, and more particularly, to a method of fabricating a light emitting device in which a metal bulk is formed on an electrode, and a light emitting device fabricated by the same.
Discussion of the Background
A light emitting diode (LED) is a solid state device capable of converting electric energy into light, and generally includes an active layer of at least one semiconductor material interposed between semiconductor layers doped with opposite conductive type impurities. When bias is applied across these doped layers, electrons and holes are injected into the active layer and recombine with each other to generate light.
Typically, a light emitting diode is used as a light emitting diode module. The light emitting diode module is generally fabricated by fabricating a light emitting diode chip having electrodes at a wafer level, followed by a packaging process and a module process. Recently, technology for fabricating a light emitting diode package at the wafer level is developed so as to eliminate a separate packaging process. As a result, this technology simplifies a fabrication process, thereby reducing process time and fabrication costs.
The light emitting diode generates large amounts of heat during light emission. This causes a decrease in the recombination rate of holes and electrons in the light emitting diode, thereby deteriorating internal quantum efficiency of the light emitting diode and reducing luminous efficacy. In order to solve this problem, the light emitting diode employs a heat dissipation pad, but still suffers from damage caused by thermal stress applied to the light emitting diode upon light emission. On the other hand, due to restriction of a growth substrate for growing semiconductor layers, technology for separating the growth substrate from the semiconductor layers has been developed. However, separation of the growth substrate from the semiconductor layers provides a problem of easy damage to a thin semiconductor layer.
Therefore, there is a need for technology capable of preventing semiconductor layers from suffering from severe stress due to heat generated during the operation of a light emitting diode and preventing damage to semiconductor layers upon separation of a growth substrate from the semiconductor layers.